Even though the gun is +P rated I have been using light loads because of the recoil in this airweight.
This is standard pressure ammo and only 110 grain. I can't understand why it failed. The gun seems fine.
I had the gunsmith at the range look at the weapon and it looked fine. I fired another 30 rounds
of Magtech 125gr FMJ after scraping out the chamber and it worked well. Should I contact S&W or
Remington? Are the chambers overly wide?

The cases could be faulty, I would get with Remington first (this is factory ammo, right?)
Improper tempering at the factory could be the fault.
When the powder burns in the case, the case is suppose to expand, effectively sealing the immediate area, then contract after the round is down range. If the temper is not correct for the pressure, you may see the cracks.
Reloading "works" the case and this will affect the temper also. That is why some cases can be reloaded many times, and others only once.

How old is the S&W? If chambers are too big (you can't tell by the eye alone), the cases still may not seal correctly. I've seen one guy who would use stones to smooth the chambers, then complain about his ammo splitting.

Either way, Good luck.

__________________
Amendment II:
"A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."

Life Member NRA
Life Member NAHC
Former President of the ECPT (Eifel Combat Pistol Team)

I have observed numerous split cases because I might reload a 38 special up to ten times. My loads are 3.0 grns of bullseye with a cast 158 gr SWC. This is light with only about 600 FPS. My goal is to punch a hole in a target. You might have purchased a pistol when the factory was using a new chamber reamer which would cause the individual cylinders of your pistol to be slightly large yet meet factory specifications. It could be defective ammo or a pistol that has problems. I would save my brass by lot and send the pistol back to the factory if the split case problem persist along with the split brass.

During cleaning at home, I noticed a burn or cut that I could not get to come off from the inside of the chamber (I marked the chamber at the range when the case failed). This was not there before, I throughly cleaned the gun upon purchase and I would have noticed this. I contacted Remington this morning.

...and...

Remington contacted me back. They are sending an address label and want me to send the remaining brass and empty cases along with the box. They said if they will refund the money and if the weapon is damaged they will conver the repair costs from Smith.